Signaling



March 5, 1935. I H. J. J. M. DE R. DE BELLESCIZE 1,993,241

SIGNALING Filed Feb. 24, 1952 I5 Sheets Sheet l March 1935. H. J. J. M. DE R. DE BELLEsclz 1,993,241

' SIGNALING Filed Feb. 24, 1952 s Sheets-Sheet 2 Me I da ZdeBeZZewcZz e,

v A220 22a Mam}! 1935; H. J. J. M. DE R. DE BELLESCIZE 1,993,241

SIGNALING Filed Feb. 24, 1932 3 Sheets-Sheet 3 "g? I d1 48 Patented Mar. 5, 1935 UNITED, STATES SIGNALING Henri 'Jean Joseph Marie dc 'Regnau ld devBellescize,-Neuilly-sur- Seine, France I Application February 24,1932, Serial No. 594,886

. f 'In-France April 29, 1931 My invention relates broadly to communication systems and more particularly to'an improved telephonic or telegraphic signaling system.

One of the objects oimy invention is to provide the circuit arrangements for a communication system by which greater amplitude of the signaling energy is made available at areceiver from a distant transmitter than has heretofore been possible under similar conditions of rated power input and similar antenna and ground conditions or transmission line characteristics.

Another object of my invention is to provide a communication system having a higher degree of selectivity for the transmission and reception of signals than has heretofore been possible under similar conditions of rated power input at the transmitter and similar antenna ground conditions or line wire characteristics.

Still another object of my inventionisto provide circuit arrangements for a transmitter and receiver wherein signals are transmitted by currents which have alternately opposite phase relationship for cooperation with a receiving system in which an auxiliary oscillator having ,a con- 25 stant phase is produced for coaction with the incoming signaling energy in such manner as to be at certain times in phase and at other times in phase opposition with respect to the'received signals.

A iurther object of my invention isto provide a circuit arrangement for a transmitter in which a double grid valve is arranged inan oscillator circuit for the production of oscillations of constant frequency, which oscillations are caused to suc- 35 cessively change in phase for the production of signaling energy. I

V A still iurther object of my invention is to provide a receiving circuit arranged to receive the alternating phase constant frequency signaling eration with a local generator for recording or observing the received signals.

Another object or" my invention resides in the circuit arrangement at the transmitter for producing constant frequency oscillations having successively changing phase for the transmission of signaling energy at increased amplitude.

Other andfurther objects of my invention reside'in certain novel combinations of circuits as set forth more fully in'the specification hereinafter following by reference to the accompanying drawings, wherein:

Figure 1 diagrammatically illustrates vention as applied to a telegraphic transmitter embodying my invention; Fig. 2 illustrates the energy and utilize such received energy in coop-' my in- 5 Claims. (01; 250-17 7 characteristic curves of one of the tubes of the transmitter diagrammatically shown in Fig. 1; Figs. 3 and 4 diagrammatically show two differential oscillations which exist at the same time in the transmitter circuit, one of these oscillations having a constant phase and amplitude while the other, which has an opposite phase, has a given amplitude during the dots and dashes, and a different amplitudein the spaces between dots and dashes; Fig. 5 represents the resulting oscillation constituting the telegraphic signal this oscilla tion having in turn two opposite'phases; Fig. 6 diagrammatically illustratesthe circuit arrange ment of my invention as appliedto a telephonic transmitter; Fig.7 diagrammatically illustrates the arrangement of the receiving circuit employed in the systemof my invention; and Fig. 8 indicates the characteristics of the currents actuating the recording relay of the receiving station, as used for telegraphic signals. 7

Signals are usually producedby means of oscillations having a frequency f,

. V s. sin 21rft (1) a whose amplitude s varies with the time but does not change its sign. For instance, in a telegraphic signal, this amplitude has a constant value +S during the dots or dashes, a; zero value duringthe periods of silence and the spaces between the dots or dashes but it is never negative. In like manner, in a radio telephonejsystem'the amplitude of the carrier wave always'exceedsthe maximum amplitude of the: whole number'of oscillations contained in the lateral bands, and hence the resulting amplitude never changes its sign.

The present invention relates to a system or communication in which the signals are produced by means of an oscillation which may be represented by the expression (1) in which the a mplitude is in turn positive or negativei It thus follows that the amplitude will always have the same sign, but the phase of the transmitted oscillation will have in turn two values in opposition such as:

s. sin 21rfts. sin (21rft+1r) Such signals cannot be received by the usual quency, but the signals may be received by modulating the signaling energy in the receiver by an auxiliary synchronous oscillation H sin 21ft having exactly their frequency and maintaining aconstant phase. At certain times, this auxiliary oscillation will be in phase with the signal, and at other times the auxiliary oscillation will be in opposition with the signal. The modulation of this oscillation by the signal produces an effective current having the form ks, in which is is a constant coeificient. This current, which reproduces the signals transmitted from the transmitting station, actuates the recording relay or the receiving telephone. r The advantage of this new system of communication consists in a more approved use of the apparatus of the transmitting station. If these latter, such as circuits, electron tubes or antennae permit the use of oscillations whose maximum .amplitude is Sm, the effective current in the re.-

ceiver will vary from to kSm for the ordinary signals, while it may vary between kSm. and +lcSm with the new system. The entire oper by reference character 1 which may be an alternator or master oscillator including a self-excited valve, producing oscillations whose frequency is f. The generator actuatesa resonator-circuit 3+4 in two different manners, directly by-the transformer 2 and indirectly through the medium of the double-grid valve 6whose sensitiveness has twovalues depending upon the two positions or" the key 10. The constant ele'ctromotive force due to the transformer 2 produces in the resonator circuit 34 a sustained oscillation whose amplitude is S3, as represented in Fig. 3. The generator 1 also excites one of the grids 7 of the doublegrid valve 6 through the transformer whose mean polarization V indicated in the curve diagram of Fig. 2 is assured by the adjustabletap 8 on potentiometer 40. The other grid 9 assumes successively two' different polarizations a1 L62 indicated in the curve diagram in Fig. 2 which are respectively assured by adjustable taps 14--16 on potentiometer 41. Potentiometer'40 is connected across potential source 42. Potentiometer 41 is connected across potential source 43. The tap 14 in potentiometer 41 is employed during'the spaces of the alphabet in which case the key 10 is moved by the spring 12 to a position in connection with the contact member 13. The tap 16 on potentiometer 4-1 is employed'for completing the signaling circuit and forming the dots and dashes, in which case the electromagnet 11 draws-the key 10 against the contact member 15. Thereversing switch 1'? whose function will be further set forth hereinafter is normally closed upon the contact member 18 on potentiometer 41. The other contact member 19 communicates with an adjustable polarizing tap 20'. The plate circuit of the double grid valve 6 connectswith the resonant circuit 21-22 wherein condenser 211 s adjustable and inductance 22 is coupled with the resonant circuit 3- -4. The polarity of thesedifferent connections is determined once for all in such manner that when the resonant circuit 21-22 is tuned to the frquency f, the oscillation represented in Fig.3 produced inthe resonant circuit 34 by means of the transformer 2 will have a phase in opposition to the phase of the oscillation produced by means of the double-grid valve 6 as represented in Fig. 4. The resulting oscillation thus produced in the resonant circuit 3-4, is transferred to the antenna circuit through the radio frequency amplifier system constituted by power amplifier tube 45, coupling circuit 46 and power amplifier tube 4'7 from which the high frequency energy is impressed upon the antenna circuit 44.

Fig. 2 shows the characteristics of the valve 6. The curve 24 represents the plate current 'i injunction of thepotential 'u of the grid 7, when the other grid 9 has the permanent potential in due to the potential derived from tap 14. Curve 25 shows the characteristic corresponding to the polarization uz due to the second tap connection 16. In consequence, when the key 10 is upon the contact member 13, the excitation of thegrid 7 by .thegenerator 1 causes the plate current y to flow in the portion 27 situated between the limits v1 and 122. 'As this portion has but a small inclination, the valvefi is hardly sensitive, and the amplitude S4 of the oscillations which it imparts to the resonant circuit 34 has but a small value;

but when the key 10 is moved into connection with the contact member 15, the plate current 7' flows in the portion 26, and hence the amplitude S5 of the oscillation imparted by the valve 6 to the resonant circuit 3-4 is much greater. By adjusting the taps 14-l6 on potentiometer 41, the

amplitudes S4 S5 can be varied at will; but before these latter are definitely adjusted the operator proceeds in such manner that the two oscillations imparted to the resonant circuit 34 will be exactly in opposition. For this purpose, the re versing switch 17 is placed temporarily upon the contact member 19 which is connected with the tap 20 on potentiometer 41. By displacing this tap 20'and at the'same time adjusting the com denser 21, the operator finds by trial an adjustment-corresponding'to a certain intermediate polarization us as represented in Fig. 2 of the grid 9 for which the current shown by the ammeter 23 in the antenna circuit 44 is zero, and this indicates that the two oscillations imparted to the resonant circuit 34 are exactly neutralized and that they have in consequence the same arnplitude S and are opposite in phase.

The opposite phase relationship being established, the reversing switch 17 is definitively placed upon the contact member 18, the contact of the key 10 is made at, 13, and the tap 14 is so adjusted that the ammeter 23 will indicate the current S1 of the character shown in Fig. 5 which it is desired to use for the position of rest or for the spaces of the alphabet. The contact is then made at 15, and the tap 16 is so adjusted as to obtain the current S2 which to be used for the dots and dashes. Since the taps 14 and 16 are situated on the respective sides of the tap. 20 for which the oscillation imparted to the resonant circuit 34, through the medium of the electron tube 6, will exactly counterbalance the oscillation of amplitude :33 imparted by the transformer 2, by the use of thetap 14 the oscillation afforded by the electron tube 6 will have an amplitude S4 which is less than S3, and that with the tap 16 the amplitude S5 will exceed S3. Thus when the key is moved to contact member 13, the resultingoscillation in the resonant circuit 3--4, illustrated in Fig. 5, and in the succeeding circuits, including the antenna circuit 44, will have the same phase withinthe scope of the appended claims without departure from the spirit of my invention.

s theoscillation s3, and it will ave the oppo i e phase (igje. the phase of the oscillation S 5) when the key is upon its contact member 15."

Fig. 6 shows the same/transmitter which is adapted for radio telephone communication. The low frequency currents from the microphone transmitter 28 modulate the circuit to the transformer 29 for controlling the potential upon the grid 9 for varying its potential on either side of a the mean value which has been adjusted by the polarizing tap 30. The carrier oscillation, whose amplitude is indicated by the antenna ammeter 23 when the microphone transmitter 28 is not spoken into, represents the difference between the oscillation imparted by the transformer 2 and the oscillation imparted by the electron tube 6, since this latter oscillation depends upon the polarization from the tap 30. This polarization can be modified in order to regulate the amplitude of the carrier oscillation to the exact value desired, for instance to one-tenth of the maximum amplitude afforded by the power amplifier stages of the transmitter. The amplitude of the microphone modulation is regulated by the adjustable taps 31 on potentiometer 48 in such manner that the modulated oscillations will be entirely in the straight part of the valve curves.

Fig. '7 is a diagrammatic view of the receiver and herein the signal (3. sin 21rft) whose amplitude is in turn positive and negative, is received by the antenna 32 tuned by resonant circuit 49 connected with radio frequency amplifier 50. The received energy then excites the grid of the detector tube 33 at the same time as the local oscillations (H sin hit) of constant phase and amplitude are impressed upon the detector tube 33 by the local generator 34. If the positive and negative values assumed in turn by the amplitude s are unequal, which is the case for instance for the telegraphic signals represented in Fig. 5 or for telephonic signals whose carrier wave has a reduced value, the local generator 34 may be synchronized by the method set forth'in my copending application Serial No. 574,858, filed November 13, 1931, for Synchronization system. But if the positive and negative values of the amplitude s are equal, which is the case for a. telephonic transmission system reduced to its two lateral bands, the local generator may be synchronized by the method set forth in my copending application.

The modulation of the signal by the local oscillation produces in the plate circuit of the detector valve 33 a current ks which is proportional to s, and this current is received by the polarized recording relay 35 or by the telephone 37. The telegraphic signals shown in Fig. 5 appear finally as represented in Fig. 8 during the spaces or the periods of rest, as a direct current whose value is RS1, and during the dots and dashes, as a direct current having the contrary sense, whose value is 7682. The total variation of the current actuating the relay is 7c(S1+S2) The reaction spring 36 of the armature is so adjusted that the armature will move from one contact member to the other when the operating current passes through the mean value shown in Fig. 8 by the line 38.

While I have described my invention in certain preferred embodiments, I desire that it be understood that my invention may be used in various forms and that the circuit arrangement shown herein are to be considered in the illustrative sense and not in the limiting sense. Modifications may be made in the circuits of my invention What I'claimas new and desire to secure by Letters l-fatent. crime United States is s- 1501- lows:

1. A transmission system comprising 'ai high frequency generator, an electron tube having a cathode, a pairofgrid electrodes and an'anode, means for applying selected potentials to said grid electrodes, an output circuit including said cathode and anode, means interconnecting said generator and one of the input circuits of said electrone tube, a resonant circuit connected in said output circuit, a power amplifier system, transmission means connected with the output of said power amplifier system, and a circuit interconnecting said high frequency generator and the resonant circuit of said electrontube forimpressing oscillations upon said power amplifier system having'successively opposite phase.

2. In a signalling system, a transmitter including a source of high frequency oscillations, a power amplifier system, transmission means connected with the output of said power amplifier system, an electron tube including an output circuit and a pair of input circuits, coupling means connected with the input circuit of said power amplifier and connected with said high frequency generator and with the output circuit of said oscillator, means interconnecting said generator and one of the input circuits of said electron tube, and signaling means in the other input circuit of said electron tube for controlling the operation of said electron tube for transferring signaling energy to said power amplifier.

3. In a transmission system, a high frequency generator, a power amplifier having its output cirmeans and separate circuits included between.

said separate grid electrodes and said cathode, means interconnecting one of said circuits with said high frequency generator, and means interconnecting the other of said grids with a telea graphic keying system. 7

4. In a transmission system, a highfrequency generator, a power amplifier having its output.

circuit connected with transmissionmeans, a coupling circuit extending between said high frequency generator and the input circuit of said;

power amplifier, an'electron tube having a cath ode, a pair of grid electrodes and an anode, a phase adjusting circuit connected between said anode and cathode and coupled with said coupling circuit and separate circuits included between said separate grid electrodes and said cathode, means interconnecting one of said circuits with said high frequency generator, and means for changing the potential on the other of said grids for the production of telegraphic signals.

5. .In a transmission system, a high frequency generator, a power amplifier having its output.

circuit connected with transmission means; a

coupling circuit extending between said high frequency generator and the input circuit of said power amplifier, an electron tube having a cathode, a pair of grid electrodes and an anode, a phase adjusting circuit connected between said anode and cathode and coupled with said coupling means, separate [circuits included between said separate grid electrodes and said cathode, means interconnecting one of said circuits with said high frequency generator telegraphic keying means; and circuits interconnecting said keying means with the circuits of said electron tube for controlling the transfer of energy from said generator directly to said transmission means at one phase and controlling the transfer of energy indirectly from said generator to said transmission means through the circuits of said electron tube at opposite phase for defining the dots and dashes of the telegraphic code at one phase and the spaces'intermediate the dots and dashes at the other phase.

HENRI JEAN JOSEPH MARIE DE REGNAULD DE BELLESCIZE. 

